Power actuator



March i, W32. c. s BRAGG ET AL POWER ACTUATOR Original Filed Jan. ,5,1925 Ill/i 016i 55m M INVENTORS Va'clarW/Klggralk Patented Mar. 1, 1932UNITED STATES, PATENT OFFICE CALEB s. 'BnAqG, or ran: .nmcn,rnonmnfnnnvro'ron w. xnmsna'rn, or soon:

BEND,

INDIANA, ASSIGNORS TO-BRAGGi-KLIESRATH CORPORATION, OF LONG- ISLANDCITY, NEW YORK, a conronnrron on NEW You I towns ac'run'ron.

Original application filed Our invention consists in the novel featureshereinafter described, reference being had to the accompanying drawingswhich show one embodiment of the invention selected by us for purposesof illustration, and the said invention is fully disclosed in thefollowing description and claims.

' This application is a division of our former application States filedJanuary 5, 1925 and given Serial N o. 506. I

Our invention relates to a power actuator adapted especially for use inconnection with automotive vehicles propelled by an internal lcombustion engine, the actuator being most conveniently operated bysuction from a suction passage of the engine between the throttle valveand the engine cylinder or cylinders, as for example by means 'of aconnection with the intake manifold of the engine,

as the source of lower fluid pressure, and a connection with theatmosphere, as the source of higher fluid pressures. In our priorapplication for Letters Patent of the United States filed December 22,1923,. Serial No. 682,346, we have disclosed a power actuator of thisgeneral type, an adjustable regulating valve or other restricting means,and a check valve being located in the suction connection with themanifold, and a storage space or tank being providedbetween the manifoldand the power actuator, which comprises a cylinder, a double actingpiston therein, and reversing valve mechanism operated by a foot leveror other operator operated part, the piston of the actuatorbeingconnected with brake mechanism forthe vehicle.

The regulating valve or other restricting device prevents such largevolumes of air being drawn intothe intake manifold as to be likely todilute the explosive charges passing therethrough so as to stall theengine while idling,.while the storage space or vacuum tank provides alarge space in which a partial vacuum is maintained at all timeswhile-the engine is running. to insure the instantaneous withdrawal ofthe necessary amount of air from the actuator cylinder when the brakesare applied.

According to our present invention we disfor Letters Patent of theUnited January 5, 1925, Serial No. 506. Divided and this applicationfiled September 1, 1928, Serial No. 308,412. Renewed July 16, 1931.

pense with any extraneous storage space or storage tank in the suctionline extending to the intake manifold exterior to the actuator cylinderand maintain a condition of partial vacuum or rarefication within theactuator cylinder itself'on both sides of the piston, the cylinderitself supplying the necessary vacuum storage space.

According to our present invention this is accomplished withoutinterfering with the normal operation of the valve mechanism, all thevalves of which are permitted to seat in the released position of theparts, the actuator cylinder being provided with an auxiliary valve forcontrolling passages which when the valve is opened connect the actuatorcylinder on both sides of the piston with the suc-' tion connectionindependently of the reversin valve mechanism, said auxiliary valvebeing normally held in the open position by the piston. I I

Referring to the accompanying drawings which illustrate an embodiment ofour invention selected by us for purposes of illustration,

Fig. 1 is a diagrammatic view representing an installation of ourimproved actuator in connection with the internal combustion engine ofan automotive vehicle for the,opera tion of the brake mechanism thereof.so

Fig. 2 is an enlarged sectional view of one form of our improvedactuator having one form of ourpresent invention embodied therein.

Fig. 2a is a detail sectional view ofthe terminal portions of the pistonrod and valve actuating sleeve omitted from Fig. 2.

I Fig. 3 isa partial sectional view illustratan internal combustionengine for propelling 3% the vehicle, provided with an intake manifold,561, to which is connected a suction pipe, 562, in which are locatedpreferably an adjustable regulating valve or restricting valve, 564, acheck valve, 565, and a vent valve, 567 normally closed and openingoutwardly. The construction of the check valve and vent valve forms nopart of our present invention and will not be particularly desdribed orillustrated herein. The suction pipe, 562, communicates with one of ourimproved power actuators, the cylinder of which is indicated at 501, inFig. 1, the said pipe having a flexible portion connected to a hollowvalve actuating sleeve, 520, and communicating with the reversing valvemechanism. The sleeve, 520, is connected by a link, 585, with the footlever, 588, which is provided with the usual retracting spring, 589, andthe piston rod, 505, of the actuator is cgnnected by a link, 573, withthe brake lever, 5 2.

In Fig. 2 we have shown one form of our improved actuator embodying ourpresent invention. In this figure, 501 represents the actuator cylinderclosed at both ends by heads, 502, connected by tubular bolts, 502 andnuts. 503 represents the double acting piston provided with oppositelydisposed gaskets, 504. 505 represents a hollow piston rod which extendsthrough the rear cylinder head andis connected at its inner end with thehub of the piston. The hub, 510, of the actuator piston is provided withtwo valve chambers, 511 and 512 respectively, each of which is providedwith two valve seats, preferably conical and concentric to the axis ofthe piston. The valve chamber, 511, is shown as provided with conicalvalve seats, 513 and 514, and the valve chamber. 512, is similarlyprovided with valve seats, 515 and 516. The piston hub is provided inthis instance with an outlet chamber or suction chamber, indicated at517, which communicates with each of the valve chambers through thevalve seats, 514 and 515. The piston hub is also provided with a higherpressure chamber, 518, in this instance communicating with theatmosphere, and-which communicates with the valve seat, 516, and by alateral passage, 519, with the valve seat, 513, at the opposite end ofthe piston hub.

520 represents the valve actuating part, consisting in this instance ofa valve sleeve passing through a stutiing box, 521, in the cylinder headat the opposite end from the piston rod, 505. said sleeve also extendinglongitudinally through the piston hub. the chambers thereof. and throughthe hollow piston rod, 505, and being movable longitudinally withrespect thereto to effect the operation of the reversing valve. Thevalve sleeve is preferably made in two parts. 520 and 520" connected bythreaded projections on a centrally located collar, 522, in the suctionchamber, 517. The collar, 522, is provided with one or more lateralpassages, 524, communicating with the interior of the sleeve section,520, through a. longitudinal passage inone of the plugs, indicated indotted lines in Fig. 2. The sleeve sections, 520 and 520, are thusconnected for joint movement, but arenotincommunicationwitheach other.The valve sleeve section, 520, is provided adjacent to its outer endwith a lateral passage, 526,

to which the suction pipe, 562, is connected, and the outer end of thesleeve section, 520, is provided with an attaching eye to which thelink, 585, extending to the foot lever is connected. The sleeve section,520, is provided with apertures, 527, communicating with the atmosphereor higher pressure chamber, 518, and the outer end of the sleevesection, 520*, which extends through the hollow piston rod, is openedand communicates with the interior of the piston rod, which is providedwith means for admitting atmospheric air thereto. In this instance thepiston rod, 505, is shown provided with a plug, 528, having lateral airinlet apertures, 529, communicating with a longitudinalaperture, 530,and the plug, 528, is also provided with an eye for enabling it to beattached to the connecting rod, 573.

The suction chamber, 517, is adapted to be connected with the cylinderon opposite sides of the piston by means of a port or ports, 534, in thevalve seat, 514, and a port or ports, 535, in the valve seat, 515. Thevalve seat, 513, communicates with the cylinder forward of the pistonthrough the annular passage, 533, and the valve seat, 516, is providedwith a port or ports, 536, communicating with the cylinder in rear ofthe piston.

Each of the valve chambers, 511 and 512, is provided with a pair ofoppositely disposed poppet valves, preferably conical, engaging theopposite valve seats, said valves being preferably formed of moldedrubber and being loose on the valve actuating sleeve, although saidvalves may be formed of other material, if preferred. The valves areindicated at 540, 541, 542 and 543. Each of these valves is held seatedby yielding'means, a rubber cushioning device, 550, being showninterposed between the valves of each pair and serving the combinedpurpose of retracting means and sealing means for the adjacent valves.The actuating sleeve is also provided with suitable means for openingone valve of each pair when the Valve sleeve is moved in eitherdirection. As shown in Fig. 2, this function is performed by the collar,522. and end collars, 531 and 532.

The specific details of the poppet valve mechanism herein shown anddescribed forms no part of our present invention as the same isillustrated. described and claimed in our fornierapplication for LettersPatent of the United States, filed November 22, 1924,

gage the pins,

and given Serial No. 751,481. From the foregoing it will be noted thatwhen the actuating sleeve is moved in either direction, one of thecentrally located valves, 541 or 542, and one of the end valves, 540 or543, will be opened simultaneously, thereby placing one end ofthecylinder in communication with the suction chamber, 517,'and the otherend of the cylinder. in communication with the atmosphere, and causing acorresponding movement of the piston in the same direction as that inwhich the valve actuating sleeve is moved. Conversely the movement ofthe valve sleeve in the opposite direction reverses the valve mechanismand effects the movement of the piston in the op osite direction.

ccording to our present invention in which no suction tank is employed,the interior of the actuator cylinder is. maintained in a state ofrarefication on both sides of the piston when the parts are in thereleased osition and the engine is running, and this is accomplishedwithout interfering with the normal operation of the valve mechanism,that is to say, in which all four of the valves of the reversing valvemechanism are permitted to firmly seatwhen the parts are in the releasedor normal position.

As shown in Fig. 2, the head, 502, of the cylinder is provided with apassage or .passages, 542 communicating with a recess, 542", in which islocated a valve seat, 542, engaged by a movable valve, 542, which valveduring the application of, the brakes closes communication between therecess, 542", and the interior of the cylinder on both'sides of thepiston. The valve is in this instance operated by a ring, 542,providedwith one or more projections, 542, extending into the cylinder farenough to be struck by the piston hub when the piston returns to itsnormal position, so as to insure the opening of the valve, 542. Thevalve seat, 542, is connected by a flexible pipe or tube, 542, with thesuction pipe, 562, independently of the connection of the suction pipewith the reversing valve mechanism through the hollow valve sleeve, 520.Thevalve seat, 542, is also connected by a pipe, 542 with the cylinderon the forward side-of the piston,as shown in Fig. 2.

From this construction 'it wilLbe noted that when the piston movesforward, the valve, 542, isseated by its frictional engagement with thepiston rod which it surrounds, and the valve may be maintained on itsseat by a light spring, 542. When the piston returns to its normalposition, right in Fig. 2, the hub of the piston will en- 542", and openthe valve,l 542 thereby establishing communication between the auxiliarysuction pipe, 542, and 'both ends of the cylinder, exhausting the airfrom the cylinder on the forward side of thepisually to the intakemanifold moving to the ton and also maintaining the partial vacuum ducedin returning the piston to its normal position.

It follows from this construction that as soon as the engine is started,the suction produced in the intake manifold will exhaust the air in thecylinder, 501, of the actuator, (the parts being in released positionand the valve, 542, opened, and the reversing valves closed) on bothsides of the piston through the auxiliary suction pipe, 542, thepassages, 542, and the pipe, 542 If now it is desired to apply thebrakes, the ,foot lever is actuated so as to move the valve sleeve, 520,in the direction of the arrow in Fig. 2, thereby opening the suctionvalve, 541, and thehigh pressure inlet valve, 543. This connects thecylinder forward of the piston directly with the suction pipe, 562, andadmits atmospheric air in rear of the piston, moving the piston forwardin a direction to apply the brakes and immediately eflecting the closeof the auxiliary valve, 542. The forward movement of the piston willfollow any extent of the forward movement of the brake lever and willapply the brakes to the desired extent without, however, admitting anyappreciable amount of air into the intake manifold through the pipe,562, as the portion of the cylinder forward of the piston is alreadyexhausted. When the movement of the foot lever stops, the piston willcontinue to move forwardly until the and brakes as applied.

reversed by the release of the foot lever, 588, the valves, 540 and 542,will be opened, eflecting the withdrawal of the air in rear piston andadmitting air forward of the piston. The air exhausted from the cylinderin rear of the piston can be delivered gradby properly regulating therestricting valve, 564, in the pipe, 562, so that the operation of theengine shall not be interfered with and the eduction of air may beretarded as much as desired, as the first movement of the pistonrearwardly will relieve the pressure of' the brakes, and it is notimportant that the piston move rearwardly as quickly as it movesforwardly to apply the brakes. When the piston is restored to normalposition, the piston hub will enga the end of the cylinder, afterengagin t e pins, 542, and opening the auxiliary va ve, 542, and thevalve actuatin sleeve willbe" arrested by the engagement 0 the fitting,526, with the adjustable follower which the stuifing box, 521, isprovided, returning valves, 543, 542 and 540 to closed positionl Theopening of the auxiliary valve, 542, places both ends of the cylinder incomof the with munication with each other and with the suotion e anequalization of-pressures on opposite sides of the piston followed bythe evacuation of the air admitted to return the piston, from both endsof the cylinder, which air will be delivered to the suction passage ofthe engine under the control of the restricting valve. This producesrarefication on both sides of the piston, leaving the piston submergedin vacuum and in condition for immediate and eflective operation toapply the brakes at any moment. We prefer to connect the valve,actuating sleeve, 520, with the piston by means providing for a limitedamount of lost motion suflicient to permit the operation of the valves,so that after this lost motion is taken up the physical power of theoperator can be directly applied to the piston and the brake mechanismconnected therewith, to' enable the operator to add his physi- 1 shownin Fig. 2a, the section, 520, of the valve sleeve is provided with arecessed portion, 520", and the collar, 520, and the piston rod, 505, isin this instance provided with set screws, 505, extending into saidrecess or recesses, 520", so, that when the sleeve is moyed forward bythe foot lever to apply the brakes and the piston has followed, applyingthe brakes to the full capacity of the actuator, the o rator may, bypushing the foot lever, 588, orward until the rear edges of the recess,520", engages the screws, 505, apply his physical force to the pistonand brake mechanism in addition to the power of the actuator. It alsofollows from this construction that should the power fail, the operatormay apply the brakes directly by his physical force, the first forwardmovement of the valve actuatin sleeve setting the valves so as to ventthe cy inder forward of the piston and admit air in rear of the pistonto permit this movement. On the release of the foot lever, theretracting spring, 589, will shift the valve sleeve rearwardly so as tovent the cylinder in case of failure of power, and the forward end ofthe recess, 520, will engage the set screws and assist in moving thepiston rearwardly to release the brakes and restore the parts to the offor released position.

In Fig. 3 we have shown a slight modification of the auxiliary valvemechanism illustrated in Fig. 2, Fig. 3 being a partial sectional viewin which the parts illustrated in Fig. 2 are given the correspondingnumerals with the addition of 100. In this construction the auxiliarvalve instead of bein located centrally o the cylinder head practicallywithin the stuffing box as illustrated in F ig. 2, is located in aseparate fitting indicated at 644, provided with a threaded portion,645, which is screwed into an aperture Lseaooo Fig. 2, and the fittingis also provided with a pipe, 642*, which communicates with the 7 otherend of the cylinder on the opposite side of the piston, all of saidpassages being closed when the valve is seated and being placed incommunication by the opening of the valve. The auxiliary valve, 642, isprovided with a valve stem, 642*, which projects into the cylinder inposition to be engaged by the piston when the latter returns to itsnormal or released position, so as to open the auxiliary valve andestablish communication between the vacuum pipe or suction pipe leadingto the manifold of the engine and both ends of the cylinder which areplaced in communica tion with each other, and thereby permitting anequalization of pressures on opposite sides of the piston when itreturns to its normal or released position and exhausting air from bothends of the cylinder, and maintaining a partial vacuum within thecylinder on both sides of the piston in exactly the same manner aspreviously described with reference to Fig. 2. t

- t will be noted that in both forms of apparatus herein shown, a vacuumis continuously maintainedin the actuator cylinder on both sides of thepiston when it is in its normal or released position and the engine isin operation so that the cylinder itself acts as a storage space, and noadditional tank or other extraneous storage space is required.

The check valve, 565, shown in Fig. 1 and interposed in the suctionpipe, insures the exhaustion of the cylinder on both sides of thepistonpermitted at any time by the operation of the engine under the controlof the throttle valve, while the vent valve, 567

provides for the venting of the cylinder should the motor stop or thesuction fail at any time and it becomes necessary for the operator toapply the brakes by physical power.

It will be understood that the brake mechanism is provided with theusual retracting means represented. in the drawings by a spring, 574.

What we claimand desire to secure by Letters Patent is 1. In a poweractuator for automotive vehicles having an internal combustion enginefor driving the same and provided with a throttle controlled suctionpassage, the combination with a part to be actuated, an actuator forsaid part including a cylinder closed for admitting a higher fluidpressure to the held in open position when the pistonjis in itsretracted position.

2. In a power actuator for automotive vehicles having an internalcombustion engine for driving the same and provided with a throttlecontrolled suction passage, the com-- bination with a part to beactuated, an actuator for said part including a cylinder closed at bothends and a piston movable therein connected to said part to be actuated,normally closed controlling valve mechanism for connecting the saidsource of suction to the cylinder on either side of the piston, and

cylinder on one side of the piston to-actuate said part, auxiliarypassages for connecting the portions of the cylinder on opposite sidesof the piston with each other and with the said source of suctionindependently of the controlling valve mechanism and valve.

means for closing said passages held in open position when the piston isin its retracted position.

3.-'In a power actuator for automotive vehicles having an internalcombustion engine for driving the same and provided with a throttlecontrolled suction passage, the combination with a part to be actuated,an actuator for said part including a cylinder closed at both ends and apiston movable therein connected to said part to be actuated, normallyclosed controlling valve mechanism for connecting .the said source ofsuction to the cylinder on either side of the piston, and for admittinga higher fluid pressure to the cyl-s ind er on one side of the piston toactuate said part, auxiliary passages for connecting the portions of thecylinder on opposite sides of the piston with each other and with saidsource of suction independently'of said controlling valve-mechanism,auxiliary valve mechanism for closing said auxiliary passages, and meansfor moving said auxiliary valve mechanism into and holding it "in openposition when the piston is in retracted p9- sition, to permitequalization of pressures in the cylinder on opposite sides of thepiston and maintain the piston submerged 'in' vacuum.

4. Ina power actuator for automotive vehicles having an internalcombustion engine for driving the same and provided with a throttlecontrolled suction passage, the combination with a partto be actuated,an actuator for said part including a cylinder closed at both ends, adouble acting piston movable therein and connected to said part to beactuated, normally closed controlling valve mechanism for connecting thecylinder on either side of the piston with said suction source and forsimultaneously connecting the cylinder on the other side of the pistonwith a source of higher fluid pressure, to effect a power stroke of thepiston, and to return it to retracted position, and auxiliary passagesindependent of said controlling valve mechanism for connecting thecylinder on both sides .of the piston with the said source of suctionand valve mechanism for closing said passages held in open position bythe piston when the piston is in retracted position.

5. In a power actuator for automotive vehicles having an internalcombustion, engine for driving the same and provided with a throttlecontrolled suction passage, the combination with a part to be actuated,an actuator for said part including a cylinder closed at both ends, adouble acting plston movable therein and connected to said part to beactuated, normally closed controlling valve mechanism for connecting thecylinder on either side of the piston with said suction source and forsimultaneously connecting the cylinder on the other side of the pistonwith a source of higher fluid pressure, to efiect a power stroke of thepiston, and to return it to retracted position, auxiliary passagesindependent of said controlling valve mechanism for connecting thecylinder on both sides of the piston with each other and with saidsource of suction When the piston is in retracted position, and meansfor closing said passages held in open position when the piston is inits retracted position.

6. In combination, an automotive vehicle having a power plant capable ofdriving the vehicle and producing a source of suction, a part to beactuated, an actuator for said part including a cylinder closed at bothends, a double acting piston movable therein and connected to said partto be actuated, controlling valve mechanism for connecting the cylinderon either side of the piston with said suction source and forsimultaneously connecting the cylinder on the other side of -of thepiston to retracted position formovanism, means for placing said valvemecha-v nism in position to close communication with both of saidsources when the piston is in a retracted position, said cylinder beingpro vided with passages independent of the passages controlled by thesaid controlling valve mechanism, for connecting the portions of thecylinder on opposite sides of the piston with each other and with thesource of suction, and auxiliary valve mechanism for controlling saidpassages, provided with a part for engaging the piston when in itsretracted poisition to effect the opening of said auxiliary va ve.

8. In a power actuator, the combination of a cylinder closed at bothends, a piston in said cylinder, reversing valve mechanism, means forconnecting the cylinder with a source 0 vacuum and with a sourceofhigher fluid pressure under the control of said valve mechanism, meansfor placing said valve mechanism in position to close communication withboth of said sources when the piston is in retracted position, anauxiliary valve mechanism located on the cylinder at one end thereof,andprovided with an auxiliary passage communicating with the suctionsource and passages communicating with the cylinder on opposite sides ofthe piston, a movable valve for closing said passages, provided withparts extending into the cylinder and engaged by the piston when inretracted position, to effect the opening of the auxiliary valve andplacing the portions of the cylinder on opposite sides of the piston incommunication with each other and with the source of suction.

9. In a power actuator for automotive vehicles having an internalcombustion engine for driving the same and provided with a throttlecontrolled suction passage, the combination with a part to be actuated,a power actuator comprising among its members a cylinder closed at bothends, a piston in said cylinder provided with means for connecting itwith brake mechanism for the vehicle, normally closed reversing valvemechanism, means for connecting the cylinder with said suction passageand with a source of higher fluid pressure under the control of saidreversing valve mechanism, means for holding said valve mechanism inclosed position when the piston is in released position, an auxiliaryvalve casing carried by the cylinder adjacent to the released positionof the piston, said casing being provided with an auxiliary suctionconnection with the said suction passage of the engine .and withpassages connecting it with the cylinder on opposite sides of thepiston, and auxiliary valve mechanism in said casing for closing all ofsaid passages, provided with parts extending into the cylinder andadapted to engage the piston when in its released position, for openingsaid auxiliary valve and placing the portions of the cylinder onopposite sides of the piston in communication with each other and withthe suction passage of the engine independently of said controllingvalve mechanism.

10. In a power actuator for automotive vehicles having an internalcombustion engine for driving the same and provided with a throttlecontrolled suction passage, the combination with a part ti) be actuated,a power actuator comprising among its members a cyliiider closed at bothends, a double acting piston in said cylinder, normally closed reversing valve mechanism provided with passages for connecting thesuction passages of the engine with the cylinder on both sides of thepiston, and air inlet passages for connecting the cylinder on both sidesof the piston with the atmosphere, controlling suction and inlet valvesfor said passages, yielding means for normally holding said valvesseated, an operator operated part operatively connected with saidvalves, and means for holding said operator operated art in position topermit the seating of all 0 said valves when the pis ton is in releasedposition, an auxiliary valve casing located at one end of the cylinderadjacent to the released position of the piston, and provided with apassage for connecting it with the suction passage of the engineindependently of the controlling valve mechanism and with passages forconnecting it with the cylinder on opposite sides of the pistonindependently of the passages controlled by said controlling valvemechanism, valve mechanism in said casing for closing all of saidpassages thereof, and means operated by the movement of the piston toits released position for o ening said valve mechanism and placing t eportions of the cylinder on opposite sides of the piston incommunication with each other and with the suction passage of theengine.

11. In vacuum brake mechanism for automotive vehicles, providedvwith aninternal combustion engine having a throttle controlled suction passage,the combination with a power actuator including a cylinder, a pistontherein connected to said brake mechanism, passages for connecting thesource of suction and a source of high pressure to said cylinder on eachside of the piston, valves for controlling said passage, means forholding said valves closed when the piston is in retracted position, andmeans operable upon the retraction of the piston to its normal positionto connect the source of suction to said cylinder on opposite sides ofthe piston.

12. In a vacuum brake mechanism for automotive vehicles provided with aninternal combustion engine having a throttle controlled suction passage,the combination with a power actuator including a cylinder and a pistonmovable therein, brake mechanism for 1 the vehicle, passages in saidactuator for connecting the suction passage and a source of higherpressure to the cylinder on each side of said piston, valves forcontrolling said passages, means for holding said valves closed when thepiston is in retracted position, and extraneous means operable upon theretraction of the piston to normal position to connect the source ofsuction to said cylinder on opposite sides of the piston.

13. In a vacuum brake mechanism for auto motive vehicles provided withan internal combustion engine having a throttle controlled suctionpassage, the combination with a power actuator including a cylinder anda piston movable therein, brake mechanism for the vehicle, passages insaid actuator for connecting the suction passage and a source of higherpressure to the cylinder on each side of said piston, valves forcontrolling said passages, means for holding said valves closed when thepiston is in retracted position, and means operated by the piston uponthe retraction thereof to normal position to connect the suction passagewith said cylinder on opposite sides of the piston to submerge thepiston in vacuum.

In testimony whereof, we aflix our signatures.

CALEB S. BRAGG. v VICTOR W. KLIESRATH.

